There is known a technique of an imaging apparatus, in which shooting (i.e. image capturing) is performed through color separation into four or more colors, and high color reproducibility is obtained by expanding a reproducible color gamut. In addition, there is known a technique, in which a spectral characteristic of a subject can be obtained by shooting an image with multiple bands, and the image is reproduced by excluding an observer's metamerism influence or a spectral characteristic of illumination light used to illuminate the subject during the shooting.
In JP 9-61244A, there is disclosed a color classification device. This color classification device includes a measurement filter group and a test filter group, each of which having a plurality of filters having different spectral transmittance characteristics. A spectral characteristic of a target object is obtained by measuring the target object while the test filter is switched. In addition, an effective measurement filter is selected from the measurement filter group based on the result detected using the test filter, and switching is performed to the effective measurement filter.
In JP 2009-237817A, there is disclosed a spectral image creating device including a first image sensor having a first spatial resolution and a first wavelength resolution and a second image sensor having a second spatial resolution higher than the spatial resolution of the first image sensor and a second wavelength resolution lower than the first wavelength resolution of the first image sensor. In this spectral image creating device, a transform matrix is created from the image data obtained by the first image sensor. In addition, a spectral image is obtained by applying the transform matrix to the image data obtained by the second image sensor.